EVIA publish Problem Statement on fan system efficiency
10/11/2020
This document is a problem statement on a future energy efficiency measure to reduce the impact of fans and increase the efficient use of fans. It is written with consideration of future revisions of European eco-design regulations but could be used by any regulatory authority to regulate the use of inefficient fans and to reduce the power consumption in the use phase of their lifecycle.
The external force demanding change can be summarised as a requirement to consider a System Efficiency Metric and Partial Load operation of the fan. Partial Load is considered as any operating point within the safe operating characteristic of the fan other than that of its peak efficiency. There are an infinite number.
Is operating at any of these points efficient? The short answer is maybe but not a definite yes. Where it operates depends on the match between the fan and the system into which it is fitted. A judgement is required to ensure an optimum match between the fan and the system into which it is incorporated. The key question is can a product regulation ensure a fan is operated at its optimum Partial Load?
Since 2011 the European Union has had an ecodesign regulation for fans, Regulation (EU) 327/2011, that has had a positive impact. It has transformed the market, removing inefficient fans, stimulating innovation, increased the use of higher efficient fans and between 2012 and 2017 saved 46,800 GWh of electricity consumption. But it is noted that it does not consider Part Load operation.
The pressure on the fan industry to adopt an Energy Efficiency Index (EEI) is not the solution and will adversely affect future development.
It is accepted that a reduction of power consumed in the use phase of fans can be achieved with better selection. A factor in forming a better decision is the availability of reliable information of the losses of the fan when operated at Part Load.
The proposal is to follow existing practice introduced in European ecodesign regulation for motors 2019/1781. This includes a requirement to provide data at a number of Part Load operating points. This ensures that components of an Extended Product are provided with reliable data. Developers can then determine the losses of their design. Further they can compare one selection to another.
The Driven Fan is a component in other Extended Products, such as ventilation appliances. Adopting the same approach in future fan regulations as those of motors and VSD regulations will provide reliable data at part Load operation. Developers of appliances using Driven Fans can then determine the impact when used at Part Load and be able to compare one fan to another, selecting the most optimum for their circumstances.
A number of issues need to be addressed in order to reach this goal. Ones such as deciding what is Part Load, and more fundamental ones such as how many operating points and how to interpolate between them.
The existing European ecodesign regulation for fans has proved to be very effective in improving fan efficiency and removing inefficient fans from the market. It is recommended to continue with this approach of setting a minimum efficiency requirement and to add to this the Part Load operating data.
The proposal is to continue with the proven approach under ecodesign. Add to it an accepted method of providing Part Load operating data. This will ensure inefficient fans are removed from the market and the power consumption of the remining fans are minimised through better selection.